1. Field of the Invention
The present invention relates to a medical instrument provided with image pickup means which is left indwelling and fixed to the inside of the abdominal wall of a patient.
2. Description of the Related Art
As is well known, endoscope apparatuses, which are medical instruments, are provided with an image pickup apparatus, which is image pickup means, designed to be introduced into a body cavity of a patient and perform various types of inspections and treatments of affected areas in the body based on observed images taken by the image pickup apparatus. Examples of such endoscopes include those introduced into digestive organs such as esophagus, stomach, large intestine and duodenum, which are tube cavities and tubes in the body, from the oral cavity or anus and those introduced into the abdominal cavity from the vicinity of the umbilical region by puncturing through the body wall.
Endoscope apparatuses for medical treatment are used in such an environment that contamination such as mucous membranes, bodily waste or blood in the body is stuck to the observation window of the image pickup apparatus or vapor is stuck to the observation window of the image pickup apparatus in a humid environment inside the body to cause fogging of the observation window, and these deposits may thereby impair visibility, preventing clear taken images from being acquired. Thus, conventionally, various proposals to remove deposits stuck to the observation window of image pickup apparatuses have been presented.
For example, Japanese Patent Application Laid-Open Publication No. 8-29699 discloses an image scope provided with a wiper that wipes contamination off the outer surface of an objective lens. Furthermore, for example, Japanese Patent Application Laid-Open Publication No. 2001-170084 discloses a tooth brushing apparatus provided with a video scope including a nozzle for removing deposits stuck to the optical window of the video scope on which image taking light impinges by a jet of water.
Furthermore, for example, Japanese Patent Application Laid-Open Publication No. 2006-55275 discloses an endoscope apparatus including an image capturing window provided with a cover glass, on the outer surface of which a hydrophilic-processed coating layer is formed, wherein contamination is removed by selectively applying ultrasound vibration to the cover glass. Japanese Patent Application Laid-Open Publication No. 2006-55275 discloses a configuration of the endoscope apparatus provided with a wiper in sliding contact with the cover glass that removes deposits.
Though not classified as a medical instrument, Japanese Patent Application Laid-Open Publication No. 2007-194931 discloses an image pickup apparatus provided with a cleaning section that deforms by receiving a predetermined stimulus applied, comes into contact with or goes away from an optical element or image pickup device due to the deformation, and thereby causes the contacting section thereof to clean deposits stuck to the lens.
As described above, the related arts adopt a configuration of removing deposits stuck to the observation window of the image pickup apparatus by a jet of water or a wiper.